An inverted-draft sliding-block bailer

Abstract

This utility model belongs to the technical field of fishing tools for special downhole operations in petroleum development, specifically relating to an inverted slider fishing barrel, including a body, a slider, and grooves. The body extends vertically, with an upper connector and a lower connector respectively connected to its upper and lower ends. The upper connector is used to connect to a milling tube of several lengths, and the lower connector is used to connect to the milling head. Three grooves are obliquely arranged from the inside to the outside on the inner wall of the middle part of the body, gradually sloping from the bottom to the top. Each groove is connected to a slider. The lower half of the inner side of the slider has transverse threads, and the upper half of the inner side of the slider has longitudinal threads. This utility model achieves the goal of effectively solving the problem of secondary fishing accidents caused by conventional slider fishing barrels by integrating longitudinal threads on the slider. Then, the threads between the fish-falling point and the slider depth are unscrewed by rotating the fishing string. Finally, the upper half of the fish can be retrieved by lifting the string.

Description

Technical Field

[0001] This utility model belongs to the technical field of retrieval tools for special downhole operations in petroleum development, specifically relating to an inverted slider retrieval cylinder. Background Technology

[0002] The conventional sliding block retrieval tool currently in use is an external retrieval tool composed of three alloy sliding blocks with transverse grooves, combined with a groove and a cylinder. The sliding blocks can slide freely within the longitudinally inclined limiting groove. Under the combined action of gravity, the squeezing force of the fallen fish, and friction, the fish is pulled upwards and brought out of the wellbore by lifting the tubing string.

[0003] For example, the prior art CN208473751U discloses an integrated milling and retrieval tool, which includes an upper connector, an extension cylinder, a retrieval cylinder, and a milling cylinder, which are fixedly connected from top to bottom. The inner cavity of the retrieval cylinder is a conical cavity that is larger at the top and smaller at the bottom. A locking block corresponding to the shape of the conical cavity is set in the conical cavity. The locking block can move up and down in the conical cavity through a slider and a sliding groove. The locking block is composed of multiple split locking plates 501. The inner sidewall of each locking plate 501 is densely covered with locking teeth 8, and the locking teeth 8 adopt a transverse tooth pattern.

[0004] However, conventional sliding block retrieval tubes have the following problems: they can only retrieve relatively light fish. If the minimum load-bearing capacity of the tubing and workover equipment is exceeded, or if the fish gets stuck in the wellbore, the upper part of the retrieval tubing can only be pulled out by inverting the retrieval tube above the retrieval tube, which is equivalent to adding more fish into the well and causing secondary accidents. Utility Model Content

[0005] The problem this utility model aims to solve is that conventional sliding block retrieval tubes have the following issues: they can only retrieve relatively light fish. If the minimum load-bearing capacity of the tubing and workover equipment is exceeded, or if the fish gets stuck in the wellbore, the upper part of the retrieval tubing can only be pulled out upside down from the retrieval tube, which is equivalent to adding more fish into the well and causing secondary accidents.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] An inverted slider scoop includes a body, a slider, and a groove. The body extends vertically, and the upper and lower ends of the body are respectively connected to an upper connector and a lower connector. The upper connector is used to connect a milling sleeve of several lengths, and the lower connector is used to connect a milling head. Three grooves are obliquely arranged from the inside to the outside on the inner wall of the middle part of the body. The grooves gradually obliquely slope from the inside to the outside from the bottom up. Each groove is connected to a slider. The lower half of the inner side of the slider has transverse teeth, and the upper half of the inner side of the slider has longitudinal teeth.

[0008] Furthermore, the inner wall of the main body is provided with three dovetail-shaped grooves, which gradually run from the bottom up and from the inside out through the main body to form three windows.

[0009] Furthermore, there are three grooves, each dividing the circumference equally and forming a 120° angle with the others.

[0010] Furthermore, the chute is tilted vertically upward at an angle of 3°.

[0011] Furthermore, the outer side of the slider is a trapezoidal male dovetail embedded in a dovetail-shaped groove, which together with the groove forms an anti-detachment track.

[0012] Furthermore, a limit step is provided at the bottom of the chute to prevent the slider from sliding out.

[0013] Furthermore, it also includes a sleeve, fitted onto the outer wall of the body, used to seal the three windows formed by the groove penetrating the body.

[0014] Furthermore, it also includes O-ring seals, with two O-ring seals sealing the upper and lower ends of the sleeve to the body.

[0015] Furthermore, both the upper and lower ends of the sleeve are connected to the body by four hexagonal screws.

[0016] Furthermore, the upper and lower connectors adopt jointless clamp-type milled pipe thread connectors.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The inverted slider retrieval cylinder of this utility model integrates transverse and longitudinal threads on the slider, so that the longitudinal and transverse threads simultaneously engage to catch the fish. Then, the threads between the fish-catching point and the slider depth are unscrewed by rotating the retrieval column (the inverted slider retrieval cylinder can be rotated forward or backward). Finally, the upper part of the fish can be retrieved by lifting the column, thereby effectively solving the problem of secondary retrieval accidents caused by conventional slider retrieval cylinders.

[0019] 2. The inverted slider retrieval tube of this utility model belongs to the downhole operation tool. Its advantages are: (1) simple structure, reliable strength, easy to process, and good on-site construction effect; (2) This utility model is a through-hole retrieval tool, which is suitable for retrieval of complex downhole fish with ultra-long longitudinal dimensions. It is generally used for large-scale overhaul construction of oil, gas and water wells; (3) This utility model innovatively integrates the inverted function, which can effectively prevent secondary stuck drill accidents caused by failure to unstick; (4) The innovative thin-sleeve sleeve design can not only flexibly replace the worn slider, but also ensure the circulation channel, prevent the alloy welding material from softening due to overheating of the milling drill, thereby preventing the milling shoe tooth loss accident, and can also return the iron filings generated by the milling from the annulus to the retrieval cup or the ground, thereby preventing them from blocking the annulus; (5) This utility model has a large retrieval range. For example, the retrieval range of this φ148mm retrieval tube can reach 110mm-10mm.

[0020] 3. This utility model is applicable to all downhole operations in oil and gas fields, and is particularly suitable for complex and challenging well workover and retrieval operations, especially for retrieving fish stuck in severely corroded ultra-deep wells. It can be used in the development of all oil fields both domestically and internationally. The benefits become more pronounced with increasing well depth. Each reduction in the number of failed retrieval attempts and stuck drill accidents improves economic efficiency and reduces costs, demonstrating broad prospects for widespread application. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the internal (external) structure of the inverted slider scooping cylinder of this utility model;

[0022] Figure 2 This is a schematic diagram of the cross-section at the middle of the slider of this utility model;

[0023] Figure 3 This is an anatomical view of the components of the inverted slider scooping cylinder of this utility model.

[0024] Figure 4 This is a schematic diagram of the slider of this utility model.

[0025] Figure label:

[0026] 1—Upper connector, 2—Hexagonal screw, 3—O-ring seal, 4—Body, 5—Sleeve, 6—Slider, 61—Longitudinal thread, 62—Transverse thread, 7—Groove, 8—Lower connector. Detailed Implementation

[0027] The technical solution of this utility model will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are not all embodiments of this utility model. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] It should be noted that the terms "center", "upper", "lower", "horizontal", "left", "right", "front", "back", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] Combination Figures 1-4 As shown, this utility model provides an inverted slider retrieval cylinder, which is suitable for high-difficulty retrieval operations of fish that have fallen into wells with large longitudinal dimensions and a wide range of irregular shapes. It belongs to the innovation of retrieval tools used in the retrieval construction process of well operations.

[0030] Taking the φ148mm inverted slider retrieval cylinder as an example. The body 1 of this inverted slider retrieval cylinder has a length of approximately 1160mm, an outer diameter of φ148mm, an inner diameter of φ110mm, and a tensile strength greater than 600KN.

[0031] The inverted slider scoop includes a body 4, a slider 6, and a sleeve 5.

[0032] The main body 4 has connectors at both ends, with the upper female and the lower male. The upper end is connected to the upper connector 1, which is a female connector, and the lower end of the main body 4 is connected to the lower connector 8, which is a male connector.

[0033] In one specific embodiment, the upper connector 1 and the lower connector 8 are jointless sleeve milled pipe thread connectors, and the body 4 is a thick pipe with jointless sleeve milled pipe thread connectors with an outer diameter of φ146mm on the upper and lower parts. The total length of the body 4 plus the upper connector 1 and the lower connector 8 is 1250mm.

[0034] The jointless coupling milling pipe thread connector is a special thread connector used in oil drilling, well workover and other operations. It features no coupling and the thread is directly machined onto the pipe.

[0035] The upper connector 1 of the main body 4 is used to connect several lengths of milling sleeves, and the internal thread of the upper connector 1 is connected to the external thread of the milling sleeve. The milling sleeve is used to connect the tubing string, and the tubing string sends the inverted slider retrieval cylinder into the wellbore.

[0036] The lower connector 8 of the body 4 is used to connect the milling head (also called the milling shoe), and the external thread of the lower connector 8 is connected to the internal thread of the milling head.

[0037] Three dovetail-shaped grooves 7 are machined obliquely from the inside to the outside through the inner wall of the main body 4. The three dovetail-shaped grooves 7 gradually obliquely from the inside to the outside from the bottom up. The three dovetail-shaped grooves 7 penetrate the main body 4 to form three windows. The grooves 7 are evenly divided into circumferences and are at an angle of 120° to each other. The vertical inclination angle of the grooves 7 is 3°, that is, the angle between the axis of the grooves 7 and the vertical direction (the direction of gravity) is 3°. The grooves 7 are slightly deviated from the vertical direction and are inclined upward.

[0038] The maximum outer diameter of the inverted slider barrel is φ148mm and the inner diameter is φ110mm. The body 4 serves to support and connect the milling head, slider 6, sleeve 5 and milling tube.

[0039] Each slide groove 7 is connected to a slider 6. The three sliders 6 are three block-shaped components machined from alloy material. The lower half of the inner side of the slider 6 (the outer side of the slider 6 connected to the slide groove 7, and the inner side of the unconnected side) is set with transverse threads 62, which are transversely machined cylindrical threads. The upper half of the inner side is set with longitudinal threads 61, which are longitudinally machined cylindrical threads. The outer side of the slider 6 is a trapezoidal male dovetail embedded in the dovetail-shaped slide groove 7, which together with the slide groove 7 forms an anti-detachment slide. A limit step is provided at the bottom of the slide groove 7 to prevent the slider 6 from sliding out.

[0040] The slider 6 is 100mm high and 33.2mm wide. The thickness can be adjusted according to the size of the fish and the retrieval range. For example, when the maximum outer diameter of the inverted slider retrieval tube is φ148mm, the retrieval range of the inverted slider retrieval tube can reach 110mm-10mm.

[0041] The sleeve 5 is a thin-skinned cylinder with a height of 1110mm, an outer diameter of φ148mm, and a thickness of 2mm. Its main function is to fit over the body 4 to seal the three windows formed by the sliding groove 7 penetrating the body 4. This prevents the circulating well fluid from short-circuiting at this point during milling and retrieval, thus preventing the washing of the fish top or milling shoe iron filings under the inverted slider retrieval cylinder and the cooling of the heat generated by milling.

[0042] The upper and lower ends of the sleeve 5 are sealed to the body 4 by an "O" ring 3, and the upper and lower ends of the sleeve 5 are firmly connected to the body 4 by two hexagonal screws 2.

[0043] Working principle and usage:

[0044] When the inverted slider retrieval cylinder of this utility model is in a natural state after entering the well, the three sliders 6, under the action of gravity, form a minimum inner diameter at the bottom limit step of the slide groove 7, which is required to be smaller than the outer diameter of the fish retrieval position.

[0045] When the fish enters the inverted slider retrieval cylinder, the slider 6 is pushed upward to a certain position. At this time, the transverse and longitudinal threads of the slider 6 only contact the surface of the fish, and the column can move downward freely. It can be milled downward or the retrieval force point can be selected downward.

[0046] When it is necessary to unblock and retrieve the tubing, simply lift the tubing string.

[0047] When the tube column is lifted, due to the upward unidirectional action of the teeth, the pressure of the groove 7 will be transmitted to the slider 6 under the action of the horizontal component of the pressure, causing the slider 6 to move radially inward, and the transverse teeth and longitudinal teeth will bite and drop the fish at the same time.

[0048] As you continue to lift the tubing, you can release the fish upwards and bring it out of the ground.

[0049] If the fish is severely stuck and the required unscratching force exceeds the equipment's load capacity, the tube column can be rotated in both directions due to the longitudinal teeth 61 on the upper part of the slider 6. This will unscratch the thread between the stuck point and the force point of the slider 6, and then lift out the tube column and the upper part of the fish.

[0050] After the fish is pulled out of the well, pull it upward relative to the inverted slider retrieval cylinder to retrieve it.

[0051] Check the condition of slider 6 and other components. If there is no obvious damage, the inverted slider retrieval tube of this utility model can be used for retrieval repeatedly.

[0052] Then change the milling shoe and perform another round, continuing to mill and retrieve the fish that have fallen down, until all the fish have been retrieved.

[0053] The inverted slider scooping cylinder of this utility model has the characteristics of reliable strength, simple operation, high construction efficiency, wide application, and cost saving.

[0054] The above technical features constitute the preferred embodiment of this utility model, which has strong adaptability and optimal implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0055] Finally, it should be noted that the above content is only used to illustrate the technical solution of this utility model, and is not intended to limit the scope of protection of this utility model. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model do not depart from the essence and scope of the technical solution of this utility model.

Claims

1. A reverse-slider scooping cylinder, comprising a body (4), a slider (6), and a groove (7), wherein the body (4) extends in the vertical direction, and the upper and lower ends of the body (4) are respectively connected to an upper connector (1) and a lower connector (8), the upper connector (1) being used to connect several lengths of milling sleeves, and the lower connector (8) being used to connect a milling head, wherein three grooves (7) are obliquely arranged from the inside to the outside on the inner wall of the middle part of the body (4), the grooves (7) gradually obliquely from the inside to the outside from the bottom up, and each groove (7) is matched with a slider (6), characterized in that, The lower half of the inner side of the slider (6) has horizontal teeth (61), and the upper half of the inner side of the slider (6) has vertical teeth (62).

2. The inverted slider scooping cylinder according to claim 1, characterized in that, The inner wall of the main body (4) is provided with three dovetail-shaped grooves (7), and the grooves (7) gradually penetrate the main body (4) from bottom to top and from the inside to the outside, forming three windows.

3. The inverted slider scooping cylinder according to claim 2, characterized in that, The three grooves (7) divide the circumference equally and are at an angle of 120° to each other.

4. The inverted slider scooping cylinder according to claim 1, characterized in that, The groove (7) is inclined vertically upward at an angle of 3°.

5. The inverted slider scooping cylinder according to claim 2, characterized in that, The outer side of the slider (6) is a trapezoidal male dovetail embedded in the dovetail-shaped groove (7), which together with the groove (7) forms an anti-detachment slide.

6. The inverted slider scooping cylinder according to claim 1, characterized in that, A limit step is provided at the bottom of the slide (7) to prevent the slider (6) from sliding out.

7. The inverted slider scooping cylinder according to any one of claims 2-6, characterized in that, It also includes a sleeve (5), which is fitted onto the outer wall of the body (4) to close the three windows on the body (4).

8. The inverted slider scooping cylinder according to claim 7, characterized in that, It also includes "O" ring seals (3), and the upper and lower ends of the sleeve (5) are sealed to the body (4) by two "O" ring seals (3).

9. The inverted slider scooping cylinder according to claim 8, characterized in that, The upper and lower ends of the sleeve (5) are connected to the body (4) by hexagonal screws (2).

10. The inverted slider scooping cylinder according to claim 1, characterized in that, The upper connector (1) and the lower connector (8) are jointless sleeve milled pipe thread connectors.

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